how do I surprise my long distance bf for Valentines?

Kay
I live in Colorado and I'm driving to Texas on the day after Valentine's to surprise my boyfriend. 
I'm driving down with our dog. I was thinking I'd have his mom take their dog for a walk and bring back our dog instead. Do a dog trade off and wait for him to stew in confusion. Lol
Or do I just knock on the door? 
Or do I sneak in and sit on the couch? 
What do you think??