How can I put this in words? Your boyfriend was a complete JACKASS.
He was extremely lucky to have you, if he has no interests in your fetish and you know he's a close minded ass then you shouldn't be with him. He's just another "normal" guy who likes tits and ass.
Seriously fuck him, find someone that actually shares your fetishes.
Let's try to avoid being completely stupid, shall we?
The gentleman in question broke up with a girl because they were sexually incompatible. Let's have a look at her picture; she's beautiful. She comes across as being sweet, warm, and friendly, and she was totally into him. Given that they were already dating, I'm assuming that--aside from this--they got along well together at one point in time. He manned up; he seems to have done it gently, he was honest about it, it's not like he walked out the door and set on out down the street merrily whistling and juggling the remaining keys from his keyring. He felt uncomfortable. If there's nothing more to the situation than this, he may well decide he made a mistake, and come looking for her again.
I couldn't tell you, personally. I wouldn't break up with a girl who had a tickling fetish. If I happened to stumble upon my girlfriend's account somewhere, however, and find out that she had an intense scat fetish? It might be time to seriously re-evaluate things. I probably wouldn't have the balls to simply end it all right there, would would likely be the best course of action--I'm unlikely to suddenly develop a fetish for something I find to be a bit of an anethema (sp), after all.
For the OP...
I'm very sorry that you had to go through this (for my part, I do wonder about the dude, just a bit). Please don't "hide your tracks." Be honest. Develop relationships at a comfortable pace. If you're with someone who knows about your fetish and simply feels uncomfortable with seeing your saved videos, that's one thing, but don't conceal it to maintain a relationship with someone who doesn't love you for who you are. Try to find someone who is compatible. Your fetish doesn't make you a freak; I won't say, "you should date someone from within the community," as that shouldn't be necessary, but I've done this before myself, and had the time of my life. Whether you find someone on the TMF or find someone elsewhere who's understanding of your fetish, I'm sure they'll consider themselves to be the luckiest guy on Earth; trust me. I'm more of a 'Ler, myself, but there seem to be lots of guys out there who'd appreciate a woman who prefers to top.