potty vs soft on

potty is a noun but soft on is not a noun.

Word	Noun	Adjective	Verb	Adverb
potty	Yes	Yes	No	No
soft on	No	Yes	No	No

As adjectives, potty and soft on are synonyms defined as:

Other synonyms of potty include enamored, in love, infatuated, smitten, taken with.

potty (noun)	soft on (noun)
a receptacle for urination or defecation in the bedroom
a plumbing fixture for defecation and urination

potty (adjective)	soft on (adjective)
slightly intoxicated	marked by foolish or unreasoning fondness
marked by foolish or unreasoning fondness
(British informal) trivial