My son and his “friend” are a couple and I don’t know how to react

I’m a 42 years old single dad of a 20 years old son. His mother cheated on me and left us when he was 5 years old. He’s the only child I have and we’re very close. I’ve never been in a relationship since his mother left. I always tried to be the best possible dad I could be for him. <br><br>A couple of months ago, he introduced me to his new boyfriend. I didn’t see it coming and didn’t know how to react but I played along, I didn’t want to make him uncomfortable. It might be because of the shock but I didn’t react badly, I just told him that it was ok and that I loved him no matter what and we hung out for a bit before he left. <br><br>They have been dating for 1 year and a half but he only told me 2 months ago. We have been texting since then but I haven’t met his boyfriend again yet. <br><br>The thing is that I’m really glad he’s happy but I didn’t see this coming and I don’t know how to react. I’m not against gay people, everyone is entitled to date whoever they want to but something tells me that I failed as a father. Maybe I should have expected this? I don’t know. What do you think I should do in this moment? Do I tell him how I really feel? I don’t want to ruin our relationship and blow things out of proportion. I really don’t want to hurt him and I want to keep being the best dad I can be for him.<br><br>I just want to say that I’m sorry if I misused some terminology. English is not my first language so I apologize if I did something wrong. Thank you for your time and attention.<br><br>TL;DR: My son (20) came out to me and I don’t know how to react.