Congrats on learning how hot pegging is. As far as a recommendation for a dildo... That will depend upon your BF's preference and just how big a toy can he take. EdenFantasys has quite a few nice toys that may "fit" your criteria. However, remember that as your BF becomes adapted to whatever toy you're using he might want to then go bigger. Of course TOO BIG from the beginning is really NOT a good thing. Happy Pegging!

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Ok omg so.
I was once recommended VixSkin dildos and they're fantastic. All I'm doing is going around telling my friends to drop the crap and pick up something that's actually worth investing in. VixSkin is - as they say in their motto - worth every inch. And it seriously is. They're dual density silicone, so there's plenty of texture to go around.

I've gotten my hands on both VixSkin Mustang and VixSkin Johnny, and I love them both dearly. Since you guys are just starting chances are, you'll want to start small, so Mustang would be the way to go. However, if you're looking for something bigger, Johnny will make both your dreams come true. These things really do spoil the people that try them and raise the standard when looking for new toys.

A thing to note about these VixSkin models - they're very, very forgiving and squishy, so they're gonna feel a bit smaller than they actually are. This squishiness doesn't get in the way of thrusting

I hope you find what you're looking for!

My current favorite is the Vixen Creations Randy but with 5-¾" x 2-¼" dimensions, it took quite a while to work up to being able to take Randy as a Pegging toy.

I'm pretty sure that I bought Randy from Eden Fantasys but that was many years ago, sadly I don't see him in the EF inventory anymore.

From edenfantasys I use Vixen Bandit, Mega, Caesar and vixen Creations Outlaw in that order. Always best to go from small to large. Lube both his ass and the toy.
I strongly recommend him cleaning out throughly before you start. Thick lubricant is also a good idea.

And make sure he's the one to wash them afterwards