Friend's mom seduction?

My friend's mom is my boss at an after school day care program. She is single and her son is a very close friend on mine. She is a beautiful in shape older woman, but I never viewed her in any sexual way because of the respect I have for my friend. At work she will tease me and smack my butt sometimes, I see it as harmless because she has a very out going personality. Well last week she asked me to come over when we got out of work and she would make me dinner and margaritas (i'm under age). So I thought nothing of it and said sure, and proceeded to follow her back after work. So she made me tuna steak and started making drinks and we walked out and ate on the deck, very harmless. Well she continued to keep making drinks and I was starting to feel a little sloshed and I could tell she was too. We talked and finished dinner and she wanted to show me the new hot tub they had gotten so she fired it up, at this point I was asking her where my friend her son was at and that I should maybe call him and let him know i'm at the house. She assured me he would be home within the hour. The conversation went back to the hot tub and she asked if i wanted to continue drinking, and jump in. I said what the hell and she proceeded to strip down to her underwear and get in with a beer. I felt very uncomfortable and nervous and said I needed to leave. Since I had been drinking she refused to let me leave and told me to relax. So I went inside and feigned being ill until my friend got home 2 hours later. Now I feel like i cant face her at work or be around my friend, I'm confused on if I should say something to my friend or if i'm over analyzing the situation. I cant talk to anyone else about this.....