Masturbating while babysitting

So I've babysat for one of our neighbors for about 4 months now. It seems like since the very first time, I couldn't wait to get the kids in bed! There's a 5 year old boy and a 9 year old girl and I usually have to give them baths before bed and I get kinda excited when I do that and like then I can't wait for them to be asleep so that l can take care of myself. I usually wait 20 mins or so and then I always go on the computer or snoop around and get so horny it's crazy.... Sometimes I will have like 4-5 orgasms and just keep doin junk till I know the parents will be home soon. Sometimes I'll even try and kinda get caught (not really) but I will start with just one leg out and keep it going till I hear them and them try to finish really quick before they get in the house.... Sometimes I feel like such a perv but it's fun! Well Saturday I was there and I was Layin on the floor in their family room and was on my tummy and was really havin fun and the little girl had gotten up and totally seen me!!... I was like uh oh! I jumped up and did my pants and she had said she couldn't sleep....I was soo nervous and I told her she could watch TV and was so scared thinkin she was gonna tell on me...so as we were watchin TV I noticed that as she was Layin there she was kind wiggling on her hand....so I didn't say anything and just kind watched her and she wound up fallin asleep after a few mins of grinding. I just couldn't wait to finish what I had started so I did it sitting up right at the end of the couch we were on... Am I bad or
like obsessed or something? Just feels so sexy bein sneaky