You have breakeven hot-and-cold equity with almost any pretty-live three-flush vs an unpaired board that has a reasonably wide opening range, which is where the rule of thumb that you should rarely fold comes from. A better three-flush (more connected with live straight cards, overcards or a small pair) would be a solid hand to continue with. This hand is none of that, it's just fairly dead garfunkle that happens to have three of a suit, and you don't think villain is stealing.
You could certainly peel if the game is full and the ante is big, but in a small pot this exact hand isn't making you money on its own. If you feel like you could do something later in the hand to win it regardless of your board, or if your opponent will overly credit you with any improvement, then you can call to set up a play with a weak redraw as backup, but mechanically throwing in a call because you see three of a suit is just treading water. If you don't play boards or hand-read as well as your opponents this is also a spot where you can easily get outplayed when you improve to a weak hand with some value.
Against a strong opening range (any pair, 3-flush, any Ace, Broadway cards) the dead, unconnected nature of your hand really hurts:
Hand | Pot equity | Wins | Ties |
---|
22+, *d*d, jt+, A* : Ad Tc | 71.46% | 428,758 | 23 |
8h 7h 2h jc | 28.54% | 171,219 | 23 |
You're in decent shape if villain's range is ATC, and in higher-ante games that will be true:
Hand | Pot equity | Wins | Ties |
---|
** | Ad Tc | 59.94% | 359,626 |
8h 7h 2h jc | 40.06% | 240,329 | 45 |
TL/DR: Call if you play well enough to own souls later, if not folding costs you nothing with this exact hand.