Actually "competing" with the other person that your spouse is having an affair with is "popular" advice on these forums, "maybe if I change my spouse will notice me and love me again" "maybe if I lose weight my spouse will notice me and love me again" "maybe if I buy better gifts for my spouse, they will notice me and love me again" "maybe if I offer footrubs to my spouse they will notice me and love me again"
Your spouse is having an affair with another person and cheating on you, you compete with your spouse's affair partner and try to out do whatever it is they're doing to get your spouse back....
Why?
Why would you reward your spouse's cheating behavior? It never works, I don't think you will find one thread on these forums where rewarding your cheating spouse in this manner has ever resulted in them coming back and having a long, lasting, loving relationship with their LBS.
Not one.
What you will find is that when you compete with the other person, you will just reinforce the idea with your spouse that they are higher value than you are, and this will enable them to eat cake at your expense - they won't just magically snap out of their condition and see what they're doing is wrong.