As mentioned previously, your room has on its bottom floor a spa. I neglected to mention that this spa is hosted in its own section of the house, only accessible from your room. That means nobody, not even silly old mom can ruin your perfect spa day. Which is exactly what won't happen now. I mean that you'll take a spa, and that it won't be ruined by Alphys.
Your relaxation room has all the things you'd expect from a moderately sized, zero-staffed spa room. It has the expected message table, the one with the little hole in one end for your face or whatever. It also has a Zen garden that forms the shape of a paradox blossom. Somewhere, in the expanse of time, your mother came into contact with the illusive Paradox Blossom and has been pseudo-obsessed with it ever since. She's tried to synthesize them, but it seems to always not work.
The spa has also a full-size hot tub, cold tub, and a saltwater hot tub. It also has a bud bath, a steam room, a plasma room, and a Bose-Einstein-fermionic condensate room. Those last two? Oh, the plasma room is a room where you can submerge yourself into extremely hot and pressurized water. The reason it's a combination of the two instead of just one is because otherwise it would be deadly to spend any time in that room. The sensation is very stimulating, as it feels like all your body is being pushed into a single point. You spend very little time in it, maybe one minute per year. The other, the Bose-Einstein-Fermionic condensate room is a room that has extremely low pressure, and extremely cold water. This one is quite the opposite of the plasma room as it feels very numbing. (think sensory deprivation tank) And so you like it because it feels strangely good. You spend a lot more time in this room than the plasma room.
Your mother, the mad scientist that she is, developed these rooms out of spite for the scientific community who thought those two states of matter were impossible to get, but they were wrong, they just needed to be made into a spa relaxation room.