Can using a triple antibiotic ointment as a lubricant during intercourse cause a white, thick, odorless cream like discharge in and on my vagina?

It sounds like it can in your case. The use of antibiotic creams may alter the normal vaginal flora and cause fungal infections that may behave very much with symptoms as you described and seeing your doc, ideally a gynecologist if established, would be best at this point.

Agree with Dr. P. If you need to , use a water based lubricant like KY jelly. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs. Get, Flu and Covid vaccines. https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines