About 4 days ago I got masturbated by a girl who covered my penis with a towel when I ejaculated. I'm fairly sure she used this towel for other guys, and I was just wondering if this is cause for concern or not? I've read around where mutual masturbation is somewhat safe, even when semen is involved, I guess I just need some reassurance and closure. The next day I had a sore throat, but I'm not sure if it is just a cold or something else.