So my boyfriend is like 5'11/6' and 143 lbs but pretty muscular and I'm 5'8 and 138 lbs (we're both 17). I know I'm not fat necessarily but he's not that much bigger than me and I always fight him when he wants me to sit directly on his lap unless I have somewhere to put my legs so I can lift some of my weight. He always really wants me to but I just always feel like I'm gonna crush him and I get embarrassed. Is anyone else like this or is it just me?