My sister calls it "muffin top." You walk down the mall or in the grocery store and see that person (man or woman—muffin top can happen to all) with a slightly too short shirt and slightly too tight pants and the stomach kind of spills out. According to my sister, it looks like a muffin. Gross, I know. Why do you think she calls it muffin top? With too tight jeans the "extra" has no where else to go but up, creating a human muffin. Ewwww! Too tight clothing is never, under any circumstances a good look—ever.
A girl in one of my high school classes was so incredibly skinny and she was really pretty; however she tended to wear really low, really tight pants and even on her stick of body she had love handles. What's worse is when girls or boys wear too-tight pants with a too-tight top—you have squeezing coming in on both sides, creating extra bulge and frankly, a not-so-attractive visual. Sometimes on girls the bulge even comes out the top of the shirt; they think it creates cleavage—it doesn't. (I don't know how they don't just spill out sometimes.) I don't know who would argue that bulge is gross, but many argue for skin-tight clothes, the creators of bulge. I just don't understand.
The first determinant of whether your clothes are too tight is, naturally, are you a muffin top? If you find yourself debating that answer, take an honest look in the mirror, or have someone take a picture or video of you. If you find you are a muffin top, stop right there and try on something new.
Another thing to consider is whether you can breathe. I know it seems like an obvious question, but if you find yourself consistently out of breath, perhaps it's time to find something looser to wear. If your shirt is so tight it looks like it's painted or tattooed on, that's a problem. Shirts that are too short are easily remedied with a camisole or something of the like underneath, but shirts that are too tight? Well, you could perhaps wear them underneath something, but still approach that alternative with caution.
Too-tight clothing goes back to the basic fashion rule of wearing clothes that fit. If your clothing is too tight then probably it is also too small. This means that when you wear it you can't help but look bigger than you actually are. My high-school girl friend was so skinny, but with those love handles she didn't really look it. It's a shame that girls and guys think "tight is hot," because the fact is it's not. (The tight look on guys is just a little weird—get some testosterone!)
Remember that fitted clothes, clothes that accentuate rather than suffocate your assets, are good, but the line between fitted and tight begins with the muffin top. We see too many muffin tops around and it needs to stop! You will look so much better in clothes that fit and honestly, you'll be taken more seriously and respected more if you don't flaunt your body in such a way. Down with muffin tops!