My first thought was that it was made with a primitive and then dforced. Never seen such a bulge. It's just a guess but i think it should be easy to do. Or instead of a primitive, a dildo.
But i don't know.
Fit control has a bulge though it isn't as blatant. Just a bulge like a man has in jeans. You can also get something like that with mesh grabber.
There might be a morph that actually has this specific bulge.
Dforce would work but would be a bit of a faf to get right.
It can be a combination of methods. You can often get decent results with careful positioning and mesh smoothing. You can then also fine-tune with D-Formers.
dForce does work well, if you have the right assets. It might struggle to fully outline the shape, though.
Like GNVE said, Fit Control has some bulge options but they don't give the sort of shape you're looking for.
Use Futalicious to add a penis to the model, then use posing to put it up against the abdomen. Using a combination of the posing and Fit Control you can get the clothing mesh to form around it. As Tessa said though, it can be a combination of methods. That one works for me when making futas.
Use Futalicious to add a penis to the model, then use posing to put it up against the abdomen. Using a combination of the posing and use the same "dForce" method used to solve big breast issue (Animation of 30 (or 60) frames, frame 1 : scale down the Futalucious figure*, at frame 20 (or 50) : normal scale, then simulate with the proper dForce settings.)