Sex with bf is suddenly great?

So my bf and I have been together exclusively for about three years now...but we have been having sex regularly for 10 years. Sex was always great with one another. Well, for the past year or so sex got really boring and one sided. Didn't last long. We went through a hiccup and I actually moved out, but we stayed together. Well, out of nowhere the sex is outstanding. He has so much passion and focuses all on me..he is pulling new tricks out of nowhere (I'm assuming from porn which is okay with me ).....but I have heard that some men get better at sex when they are seeing another woman or have been. Even though I have moved out, we see each other like four or five times a week and I always stay the night. Do you guys think he may be talking to/possibly sleeping with another woman ? Or he is just missing me and wanting things to be better between us?