I was a teenage life guard one summer at our neighborhood swimming pool and I had arrived fairly early one morning. I was double checking that everything had been picked up from the night before. I checked the grounds, then checked the boy's dressing room, and finally the girl's dressing room. While in the girl's dressing room, I picked up a girls bathing suit that had been left from the night before. For some reason I felt a stirring in my crotch area as I fantasized what the girl that wore the bathing suit must have looked like without it on. I reached down and squeezed my rapidly hardening teenage prick through my bathing suit. It wasn't but just a few seconds before I had the overwhelming desire to masturbate. I untied my bathing suit and dropped it to my ankles and proceeded to rub, squeeze, and massage my dick. It was up on a big time bone when I sensed that I wasn't alone. Sure enough, standing by the door was one of my fellow female lifeguards staring intently at every move that I made. I said OMG, reached for my bathing suit that was around my ankles, and frantically tried to pull them up as I was also trying to apologize by saying 'I'm Sorry', 'I'm Sorry','I'm Sorry' !!! She quickly blurted out 'Don't Stop, I have never seen a boy jackoff before and I would like for you to continue and let me watch you.' All I could say was that 'I'm Sorry' and finally she just point blank said either you continue and let me watch you or I will tell everyone what I caught you doing in the girl's bathroom. Not having much of a choice I dropped my bathing suit back to my ankles and proceeded to start work on my now very deflated prick. It wasn't long before it reacted and with the added excitement of her intently watching every stroke it rose to a full fledged hard bone. As I stroked it up and down I glanced over at her and she was rubbing herself through her bathing suit. This got me more excited and my cum juice started leaking out of my very excited cock head. She came up closer and was still massaging herself on top of her bathing suit
When she asked me if there was anything she could do to help me and I asked her to pull down her top so I could see her gorgeous titties as I jacked off. She pulled down the top revealing two absolutely gorgeous breasts with full soft coral tip nipples. This just about put me over the edge and I told her that I was going to cum and shoot my wad and she told me to go ahead because that is what she wanted to watch. All the time she was frantically rubbing her pussy as she watched me. We almost simultaneously went off at the same time as I shot spurt after spurt half way across the dressing room and onto the floor and she started shuddering and shaking. When we were both through we quickly redressed and took some paper towels and cleaned up the puddles of cum. As we left the dressing room we both thanked each other. This was never repeated or mentioned but there were many times during the summer that I would look at her sitting up on the lifeguard stand and remember those gorgeous tits and her masturbating herself and I would get an instant hard on which I would have to quickly cover up.