Does my unusual way of masturbation cause damage to my penis?

My way of masturbating is probably the most weird and unusual way around, I decided to ask whether it harms my penis,  let me explain.

I started masturbating when I was young, fully clothed, though is either lie down and facing the floor with penis get squished when it is not erected, I also hump on some corners of a furniture when I was younger. I am a male and an asexual sexuality.

As I age (now as a young adult), I prefer to masturbate with my favourite pair of underwear, sometimes with a speedo after swimming. Again, weird, "girly" ,(again, I am an asexual male) unusual way. I dont really like nudity and turn hard to bikini models (can be from anime too) everytime. I never take off my underwear everytime I masturbate

When my penis is not erected, I would masturbate by pushing my penis in like how females masturbate, on my favourite pair of  underwear.

When I have an erection, since my penis face really down to the feet when it erected, I push it further down with my underwear preventing it from going up, gave myself a wedgie, and push my bulge down. It does feel quite hurt as it erected but somehow I like it. I also stroke my erected penis with my underwear on. 

I am also uncircumsized.

I just curious if this is actually bad for me.