>>18510810 (OP)
I don't know, present it as "something fun" like to watch but don't over hype it, be honest that it can have lots of bad segments and it can go on for too long sometimes but some of it's really good.
Sell it as something you want to do together and later bite the bullet and watch something she wants to - It's important that it's dressed up as something that WE do.. It's important to sell any dating activity as if it's about both of you because that's what they want because THEY need the attention - if you are lucky they'll watch with you, or if they aren't interest, maybe they'll read a book next to you while it's on - that's fine too, they don't have to be into what you do but into being in your company.
Additionally sell it as sentimental you want to share. You remember watching with your dead dad/friend/cousin/dog as a kid and it takes you back. Make up if you have to but don't make up shit that comes biting you in the ass later on. This enters the "feels" and bonding area of dating and is more acceptable that wanting to do something because of your selfish needs.