A tiny, and a giant. Obviously you being constantly seen and found was going to be the biggest obstacle with this relationship. Case and point, you slipped and fell into her breasts, and the brunette was entirely unaware of it! Just now did she realize that you were gone from the perch that she had you on.
Thankfully Diane has caught on, and right now she was inspecting her body looking for the little speck. You were jumping around and waving your arms frantically. You gave up on trying to shout for her name, knowing that there was no chance for your voice to reach up to her.
While you were jumping and bouncing around, Diane was having trouble locating you. She was starting to realize how tough it was going to be to look after someone like you and travel with you. She's going to have to think of several ways to make sure you are secure, so you don't go loose and potentially fall off her body.
Turns out this time... she did find you! She saw the slightest movement from down on her chest. Jumping around and frantically trying to get her attention. She brought her neck down and closed one eye to see you better.
"THERE YOU ARE~" She smiled, spotting you. When the giant did... you took a break and relaxed. That's awesome, you can now relax and- "HOW DID YOU END UP DOWN THERE HUH~" You heard the mocking and teasing tone from the giant, Diane sending a gorgeous smile down at you, showing that she wasn't angry about where you were at all.
Now you could try to shout and explain you fell off her body, but you assume that she can piece that together. Doesn't change the fact that she was going to keep teasing. "I THINK YOU SUBTLY SNUCK DOWN THERE WHEN YOU SAW THE CHANCE. HIHI, I CAN'T REALLY SAY I BLAME YOU CUTIE, THEY WOULD BE THE BIGGEST BOOBS YOU HAVE EVER SEEN IN YOUR LIFE." She was entirely right there. So big that you were able to stand on top like you were standing on top of a cliff. Not a small one either, one so big that there could be a whole gated community living and thriving on top! "ONLY BECAUSE I'M SUCH A NICE GIANT, I'LL LET YOU STAY THERE, BUT LATER ON YOU GOT TO DO SOMETHING FOR ME. I'LL THINK OF SOMETHING FUN." This... you were not so much excited about. Can you trust Diane to have some giant/tiny fun? She's good with handling humans, but you were a lot smaller than that.
You just wait and walk around on the boob, Diane spent the next few minutes not moving, just watching your little bug-size body walk around. It was a bit unnerving, but you were able to easily ignore that, considering the fact you trust Diane entirely.
Yes the extra size she had does make it more difficult for her to take care of you, compared to what a normal-sized person would, but you trust Diane and you want to stay with her despite the immense size difference.
Same with Diane. Normally... she didn't like being bigger than everyone. Yes, she liked the perks of it, but she did envy them sometimes. Now though... she liked being bigger. She liked looking at her chest, and spotting her friend who was a mere speck on her giant, mountain-like body.
She wants to spend her time with you, and never lose you.
"I'M THINKING, I NEED YOU TO BE SECURE... IN A PLACE THAT YOU ARE NOT GOING TO FALL OFF FROM. SO IT'S YOUR LUCKY DAY, I WANT YOU IN HERE." Diane moved her colossal fingers over to her jumpsuit and pulled the clothes. just enough to show you the hidden cave that was her right tit. Just right next to the cleavage. She didn't have a bra on, her orange-outfit was tight enough. So you just saw straight into the glory. "IN THERE, YOU SHOULDN'T GO FLYING AND FALLING OFF MY BODY, AND I'LL KNOW EXACTLY WHERE TO GET YOU. JUST DON'T GET TOO PERVERTED IN THERE~" Ignoring the teasing, you can't argue that it would be best. With her suit over you, you would actually have a ceiling. You were able to stand on the boobs good enough as it is, but you would be a lot more secure than exposed.
So... you get moving. Walking over to her pulled up clothes, knowing that you were going to be closer to her nipple than you otherwise would be.
"COME ON, CAN'T YOU GO ANY FASTER?" Diane pouted from above and... that's not on you. Your legs just weren't big enough to traverse the giant terrain that was her breasts. However the giant above you smirked. "WELL I KNOW HOW TO HURRY YOU UP~" With her other hand, she brought her finger down and slammed it into the boob behind you. A giant finger from god, it felt like, and you were lucky you weren't smushed.
Or so you thought, before the finger started to drag over the top of her tits, towards you! You were going to get swept up and run over by the finger, if you don't move!
Now with purpose, you sprint to where she wanted you to go! This time, a lot faster.
Diane dragged her finger intentionally slowly, watching the little mite man running in fear. She gave out a loud, powerful laugh, loving the sight. Before, she bit her bottom lip just watching you run from her all-mighty finger, to her almighty boob.
She really likes being this big with you! Once under her clothes, she stopped the approaching finger and let go. her clothes snapping back to her tit, which did enclose on you!
However at your size, you still had plenty of room to be.
"THERE, ALL HIDDEN AND PERSONAL~" Diane happily remarked, before she started to walk again.