This store seems to have everything. Searching its cavernous depths, you find a whoopee cushion that fires blasts of bowel-like sound loud enough to deafen an entire crowd, a flower pin that squirts not water but clown makeup onto peoples' faces, and even a pen that squirts ink that's not only invisible but also completely intangible (apparently, the prank is on the prankster who buys that one). Of course, you try all of them out, entertained by even the simpler tricks that they set off and delighted at the thought of using them on your friends.
Eventually, while you peruse the seemingly endless supply of practical joke supplies, you come across a particularly weird one. Labeled "TRICK BRA", it looks to basically just be a plain red bra. It does have a bit of extra padding or something over where the breasts would go, but you can't see the "trick" in it. Curious, you do what any sensible person would do in your place: you try the bra on. Taking off your shirt, you place the cups over your flat male chest, reaching back to get the clasp hooked. It takes a bit more effort than you'd expected, but eventually you finally get it on, and the second you do the trick is revealed, a "FSSSSSSH" noise as you feel something thick getting sprayed onto your chest, almost like a spray cheese. Looking at it, you see what appears to be a flesh-colored lard filling the breast cups, giving the appearance of large-breastedness. The fact that what feels and looks a bit like animal fat is being poured all over your chest is a little disgusting, but you find yourself unable to do anything but laugh until the bra stops filling out, reaching a generous DD in size.
Wiping the water from your eyes, you reach to the clasp at your back. It's much harder to get it undone thanks to the way it's been stretched by the stuff that poured out of it, but after a few tries you finally manage to get it off, dropping the bra to the floor. You expect the "breasts" to drop with it, but instead they stick to the chest. Maybe the stuff was meant to have some extra stick? It's hard to tell, but if so it must be pretty good at it - you can feel the weight of those fake jugs on your chest, and they aren't exactly light. Whatever the case, it's not like you can't just pull it off yourself. You'd just have to grab where it connects to the chest and...
Slight snag: you can't see where the "lard" ends and your skin begins. Slightly larger snag: the lard doesn't look or feel like lard anymore. It looks like skin, and it feels like skin. In fact, both of those breasts feel and act just like the real thing - you KNOW they've got to be fake, as you can't feel anything through them, but they LOOK completely real. You try tugging on one, hoping that the seam's just hard to spot, that it'll come off if you just give it a good pull, but all you get out of that is the pain of feeling your chest being pulled with the breast and (rather surprisingly) a squirt of milk coming out of the breast itself. So they're definitely not real... but they feel real to the touch, they look completely indistinguishable from a world-class rack, and they're LACTATING?!? This is not good.