Love and Grindr

I have been on and off hooking up with this guy for about 2 years now. We had been working together until just recently which is part of the reason it was "complicated". About a month ago we were enjoying some day drinking and got a little drunk and started hooking up. This was the first time we had hooked up with each other in several months. Before either of us had our clothes off he whispers in my ear, "I love you". Being drunk and having mutual feelings I replied back, "I love you too." I then asked him about how long he had loved me and he said about a year to a year and a half at most....about how long I have had feelings for him too.Later that night we started to feel hungover so we went to get some food. While we were eating, he pulled out his phone and I look over and see Grindr on his phone as he quickly exits out. I didn't say anything at the time because I didn't know what to say especially because I have a tendency to be a user of that app as well. Needless to say it has definitely been on my mind since then. Since then we have been spending even more time together and just last weekend we had the best sex of my entire life.We have never talked about "us" because it is very very complicated but I feel we need to have a conversation about what our relationship is very soon. I want to ask him about Grindr, defining our relationship, being exclusive and what the future looks like but I don't know how to bring up the Grindr part. Should I start with the Grindr situation? It might break the ice but it can also be a very blunt way to start a conversation that I want to lead to a relationship. How do I bring it up and not look like a stalker but still be honest??Thanks :)