spotting

Dear Betty,

I am a bisexual woman in a long term relationship with another woman. Recently, we had a threesome with a male friend, which for both of us was the first time having sex with a male. My lady and I have used sex toys, and achieved penetration in other ways, so I guess it surprised me a little when I bled after having intercourse with the male. When I hear talk of the hymen, it's described as being along the lower edge of the vaginal opening, but I think my bleeding is coming from the upper area. We have done this twice now, and while I bled less the second time, I still did. It continues lightly for a day or so afterwards. The male does have a penis on the larger side, which I am sure is a factor. I guess I am wondering - is there any bleeding resulting from sex that I SHOULD be worried about?