If two people have a brief romantic relationship, you can say that they have a dalliance with each other, especially if they do not take it seriously. [old-fashioned]
...my dalliance with a certain footballer.
...sexual dalliances.
2. countable noun [oft poss NOUN]
Someone's dalliancewith something is a brief involvement with it. [old-fashioned]
...my brief dalliance with higher education. [+ with]