Online dating

How would you all feel if your s/o had been on a dating website. I had gotten on his phone bc I thought he received a text message while in the shower and we was waiting on one of his friends to come and I thought it might be him. Instead it was an alert saying he received a message from a dating website called "plenty of fish". When I asked him about it he said he thought it was a social media site like Facebook. He said he was just getting on it bc his friends told him about it and that's what he thought it was. If you even look up the website it clearly states it's a dating website. So i went on there and began to make aprofile to see if it could be confused with something like Facebook and the questions it asked was obviously adating site. I was honestly hurt bc I felt like he was trying to find somebody else but then I want to give him the benefit of doubt. Opinions?