Yo mama's so fat, she often impersonates Saturn by wearing a tutu.
Yo mama's so fat, her pants' length is measured in light-years.
Yo mama's so fat, she is as geographically useful to to the inhabitants of Gliese as Polaris is to us.
Yo mama's so fat, the escape velocity at her surface exceeds 3x10^8 m/s.
Yo mama's so fat, she is as dense as a neutron star. (or black hole, for better effect)
Yo mama's so fat that if she stood up and looked down at the Earth, she'd be watching Jurassic Park (live?).
Yo mama's so fat, she could very well be the dark hole at the center of our galaxy.
Yo mama's so fat, her heart's a pulsar.
Yo mama's so fat, she uses the Earth as her personal globe when taking a geography class.
Yo mama's so fat, she's good friends with Xenu.
mama's so fat, she made love to the sun and gave birth to nonuplets
(nine-tuplets). Considering this was too much for her to handle, she
eventually had to estrange the smallest of her children.
Yo mama's so fat, she has a mass whether or not the Higgs-Boson exists.
Yo mama's so fat, NASA have launched satellites to orbit her.
Yo mama's so fat, dark holes are her personal toilets.
Yo mama's so fat, that when at her perigee, we can see her skin cells reproduce.
Yo mama's so fat, she farted on Jupiter and created the Great Red Spot.
Yo mama's so fat, she has such mass as to completely bend space-time around herself, such that even light could not escape. (Yet another black hole joke. You may make your own whore references if you like)
Yo mama's so fat, astronomers use her for gravitational microlensing.
mama's so fat, she'd be considered a magnetar if she clapped. That is
why, for our sake, she must never be amused by anything. Or have a space
mosquito/shuttle bother her.
Yo mama's so fat that the only plausible explanation as to how she achieves such great size is due to the fact that she travels so close to light speed.
Yo mama's so slow that her De Broglie wavelength is observable on macroscopic scales.
Yo mama's so old that we can see her in the photographs taken by the Hubble Space Telescope; she's way in the back of all of the other celestial objects and is bright red.
mama's so easy that in the many worlds interpretation of quantum
mechanics, I've slept with her in every
Yo mama's so cold, she hit absolute zero. (which happens to be impossible)
Yo mama's is so obviously visible, nobody knows her momentum.
01101111 00100000 01101101 01100001 01101101 01100001 00100111 01110011
00100000 01110011 01101111 00100000 01110011 01110100 01110101 01110000
01101001 01100100 00101100 00100000 01110011 01101000 01100101 00100000
01100011 01100001 01101110 00100111 01110100 00100000 01110010 01100101
01100001 01100100 00100000 01100010 01101001 01101110 01100001 01110010
Yo mama's so fat, she collapsed the wave function by sitting on it.
Your mother is so corpulent, people construct marginally humorous jokes about her.