It is generally not advisable to keep goldfish and kissing fish together. Kissing gouramis can grow larger and may bully or eat goldfish. They can be territorial and aggressive, especially during spawning. They also prefer different water pH levels (6.5–7.5 for kissing gourami vs. 7.2–7.8 for goldfish) and may compete for food. Keeping them separately is best for their well-being.