I was super-bummed because Erik the Slayer had disappeared somewhere and never returned to Rorikstead, and he was the follower I wanted to marry.

Well, by chance I ran into him hanging out at the Western Watchtower and he joined up with me again.

Happy ending, right? Wrong!

He ignores my Amulet of Mara completely. There is no "Interested in me, are you?" dialogue option when I'm wearing it.

Not only is he supposed to be eligible, but I am using the UFO followers mod that is supposed to make every follower a marriage option.

Could it be the mod itself messing him up?

No that mod has a number of problems. Go to the fairy and disable it properly, then marry him and re-enable it. Save before you do so because I'm not positive this will work. Oh, and dismiss him before disabling the mod or it will RUIN him.

edit: great mod though, hold on to it

Thanks, I'll give it a try

Erik is not intended to be a candidate for marriage, despite the fact that the other hirelings are eligible.

You can still add him to the faction. If what I said doesn't work, use this console command,
click Erik
setrelationshiprank 4
addfac 19809
getrelationshiprank(to check if it's 4-lover)
and he should now be an eligible candidate for marriage.

Poor Erik is denied marriage by those cruel, cruel Beth employees. He's destined to travel alongside the Dovahkiin, watching, longing, wishing, forever friend-zoned.

Erik the Slayer is listed as a marriage option in the guide, but it seems the Amulet of Mara is outside the spectrum of his vision.

Thanks. Should I also do that with the UFO mod uninstalled? (Making all followers eligible is one of the things the mod supposedly does.)