Have you ever cum in your pants?

Yes dry humping a friends ex girlfriend. She had big tits that I was sucking on at the time. She just wouldn’t let me fuck her. 

Yes. More than once if I got too excited.

Yes twice in my younger days. Once while eating a young girl's pussy, and another with my hand down a gir;'s panties giving her a good fingering. A question to the 'asker' have you ever cum in your panties?

like while wearing 'em, or just like, standing over 'em cumming?

YES. I cum in my underwear and it was because I was looking at this woman in a red plaid / tartan pleated skirt, and she bent over to pick up her parcel from the floor and I just had become rampant watching her, and I shot my load into my pants, as she turned around, she must have seen my face all red with a sex flush, and asked me are you all right sweetie? I was nineteen, and her in her sixties. I had the courage to tell her what had happened and why. I knew the woman, so she said we best get them off you sweetie and a clean pair on you, after I clean you up down there. She gave me a ride to her house, as she lived alone, told me to strip off to bath me. It be all right ma-am, but she insisted and told me not to be shy or embarrassed as she had seen many a young man stark naked, being a retired nurse. I sat in the tub of tepid water as she was me allover, paying particular attention to my genitalia, which made me erect. Are you going to wash my underpants or am I, I asked? Neither of us are sweetie, I have binned them. I need underwear to go home. You shall have underwear my girl, a pretty pink panties I bought a pack of four of for my daughter, but she told me she does not wear panties like that now.Oh my gosh, my om will see them and ask whose they are? Well tell her the truth my girl, and say they are yours. Why are you referring to me in the female gender I asked? Well baby doll, boys don't wear girl's panties, do they? I bet your mom will like you in them. Does your mom still bath you, like I am doing now? Before you step out of the tub, I shall shave off your bush there my girl, as many a woman does these days. No please don't. My girl, you are not in a position to protest here, with you nude in my bath tub and your clothes hidden away. We are going to have such fun before you go home. What are you going to do to me? Well as you have been a very naughty little girl, first you shall be over my lap nude and shaven, to be spanked. then baby doll you shall be dressed in a very pretty dress of mine to curtsy, twirl and prance around the lounge while I record it all. You shall look so cute without that horrid pubic hair on your girly privates.

You coulda just said "yeah."

I don't think so, at least when I was awake. Would much rather wait and find a private place where I can whip it out and jerk off properly.

Asleep ... even then, I've only had a nocturnal emission once in my life. We had houseguests, and I'd gone over a week without masturbating, and in the middle of the night my body decided it had gone too long. I guess normally I jack off plenty often enough to prevent this from happening.

Yes, In high school during a dance rehearsal for the spring musical. My partner, who I had a huge crush on, was trying to teach me how to dip her as part of the choreography for a dance routine. Her groin kept grinding against my leg and I ejaculated. I was able to hide it but I was really embarrassed.

Yes, but my favorite way was when my girlfriend would grind her clit and pussy on my erection, both of us fully clothed

Yes.