Is it normal that i get off watching lesbian porn but still love my bf

Sorry about my spelling and punctuation if there's any major mistakes.

To make this easy and simple all just go straight to it.

I have a boyfriend and I have been with him for 4 years. I'm 19 he's 24. I do love him very much!

Since I was 15 something like that I have liked the female body mainly the boobs though that's really it. Like if I was to see a pretty girl with a nice figure I would look and think she has a really nice body, I wish I had a body like her's!

I like to watch lesbian porn and it does do the job for me. For an example like lesbians sucking each others tits is what I like to watch. Don't get me wrong I do love having sex with my partner as well.

I have had a threesome that does involve another girl but us girls we were drunk and couldn't exactly remember what really happened and fully remember what we had done to each other.

I have fantasised about girls boobs before while doing something to myself.

It has only been the last 3-4 moths where I keep panicking about turning bi or lesbian not that I have anything against them it's just that I don't want to become bi or lesbian.. I couldn't imagine being in a relationship with a female.

I just keep asking myself am I bi? or lesbian? and is it normal to be sexally attracted to the female body more the boobs than anything and still be straight?