The Preemptive Breakup
He's going to get dumped--guaranteed. He's panicking and trying to rapidly increase IL. Getting all sorts of advice about mystery dates, etc. That stuff works in a healthy and/or new relationship but when the woman is losing interest, the ONLY thing you can do is hit the eject button before she dumps you. This way, it's (usually) a shock and awe move that can really pique her interest. BUT, you need to have pair of brass balls and stick to it. Here's where 99% of all men are too chicken s*it to do it. He needs to talk with her and say, "Hey Sally, damn this is hard, but this just isn't working for me anymore. I think you're an awesome person but I need some time to process how a LTR will fit into my life right now. It's not fair to you that I'm not in this 100%. I need some time to process. I hope you understand." I've done this a few times and had the girl blowing up my phone and doing an about face.
Then, stick to what you said for at least 60-90 days. Chances are you'll meet someone new and/or lose attraction for Sally by then. NO CONTACT IS ALLOWED. Got it? She may not give a s*it, but maybe her hamster will spin too. Either way, you don't care. If after 60-90 days, you want to have a chill date, do it, and it's like hitting the reset button--but SHE must reach out, not you, no matter what. Don't be a p*ssy. Got it?
At least this way you preserve you dignity, manhood, and pride, and know you're the one who ended it, which from a psychological perspective, will help your confidence as you find someone who is a better fit.
BUT, my guess is OP will read this and not do it. 99% don't. So for the guys that asked, there you go. Employ the Preemptive Breakup when you sense it coming and take back your power and dignity.
Be well.
~Dash~