Of course with hands.
but there's a way to do it. Here's how:
sit next to each other. casually, touch her hands first. if the response is good, continue to touch her stomach. go up a little. later touch her breasts.
OR Touch her neck. just slide down. if response is good, go down. reach her cleavage circle around but don't touch her nipples. touch all the most ignored areas. finally. start circling her aerolas. next pinch or squeeze her nipples. squeeze her whole breasts. then start to suck. while sucking, you can also rub her clitoris.
While u r in a crowded bus, sit just in the sit in which SHE i facing. when the bus is pullin' brakes, try to touch hr brsts with ur head. Believe me, she won't mind... She'll just take it in a casual way...
BUT DON'T TRY TO DO IT IN A EMPTY BUS.
When you touch a females breasts you shouldn't be to rough because it does hurt the female if you put to much pressure on her breast.