I'll suggest 'joshes about', because that means
To make ... good-humored jokes....
[josh. (n.d.) American Heritage® Dictionary of the English Language, Fifth Edition. (2011). Retrieved January 18 2016 from http://www.thefreedictionary.com/josh .]
Of other options, only 'ribs' and 'chaffs' suit your desire for a term "less intense than 'ridicule'". Of those two options, 'ribs' is the better one, because 'chaffs' is both colloquial and nuanced as described in the OED Online:
a. trans. To banter, rail at, or rally, in a light and non-serious manner, or without anger, but so as to try the good nature or temper of the person ‘chaffed’.
(A word or sense which probably arose as cadgers' slang, and is still considered slangy, and usually apologized for by inverted commas.)
["chaff, v.2". OED Online. December 2015. Oxford University Press. http://www.oed.com/view/Entry/30164?rskey=OwtKJW&result=4&isAdvanced=false (accessed January 18, 2016). Emphasis mine.]
Other options such as 'mocks', 'lampoons', 'sends up', 'pokes fun at', 'scorns' and 'derides' would all need to be qualified with, for example, 'light-heartedly' or 'good-humoredly', in order to be sure that they were understood to be "less intense than 'ridicule'".