i used to want to fuck him with a strap-on, huge huge huge fantasy, and then he bought me one…
the first time i put it on, i was alone while he was away. i had an amazing night with it….amazing. ha! that doesn’t even come close to how i felt. it was incredible, almost beyond words....
almost 
but besides just being fun, it gave me a chance to get comfortable with it, learn it so to speak.
the next time it was brought out of the naughty drawer, we were together and he used it on me—a little double penetration. great sex, fantastic sex, but not as good as when one of us uses a hand to move the dildo, cause i can get that off-rhythm pistoning; the dildo going in while the cock slips out. omg, i love that.
and then i finally used it on him. it was just a teensy bit awkward because of me and my inhibitions but also ‘cause the dildo isn’t really firm--it gives a bit--so i had to keep it steady with a hand when what i really wanted to do was grab onto his hips and his cock and fuck him senseless. and i wanted to FEEL it. jesus, did i want to feel it. the flat of the dildo pressed against my clit, and that felt incredible, but i really wanted to feel the tightness, the grip and pull and draw and i slid in and out of him. it wasn’t a letdown--believe me it wasn’t--but it wasn’t as easy as i had expected either. i wanted to fuck him and stroke him and caress his body and kiss his mouth and lick his chest and grab his ass but i couldn’t do all i wanted cause i need almost all my concentration to hold the strap-on in place. we’ve done it a few more times since then, and i’m getting a bit more adept.
what i really want next is to use the bigger dildo on him (he’s a bit scared of it though lol)and practice some more.
as to why? i dunno really. it’s sexy, it’s animalistic, it’s domination, it’s pleasuring him…and me. it’s just plain hot and i love it. but i really love that he bought one just for me because he knew it was a fantasy. and now it is a fantasy fulfilled a few times and a fantasy that we can indulge in whenever the mood strikes.