Vygotsky's theory of cognitive development is one of the most solid foundations of constructivism. The gist of it states that the process of cognitive development is a major product that comes out of social interaction, no matter what age, since people all develop and acquire knowledge at a different rate.
In Vygotsky's own words:
“Every function in the child’s cultural development appears twice: first, on the social level, and later, on the individual level; first, between people (interpsychological) and then inside the child (intrapsychological).” (Vygotsky, 1978).
With the help of peer interaction anf the MKO's (More Knowledgeable Others), an individual can aspire to acquire more information, nee Intelligence, and higher level thinking occurs.
Contrastingly to this, Behaviorists and Cognitive Theorists both agree, however, that sexual orientation (particularly homosexuality) would be the product of a construction gone wrong, that is, that perhaps the needs of the individual, or that the social interactions and exposure to others was what caused sexual orientation to deviate. Heterosexuality, though arguably occurs in the same manner, is seen mostly as an automatic response resulting from our genetic make up.
In using V's theory to explain sexual orientation, a scenario can surface where a person gets influenced by another one in certain practices that, to the individual, bring satisfaction to their needs. Hence, the person who influences the other becomes the MKO in that specific emotional period, and with enough interaction and exposure the individual decides whether their sexual orientation goes with or against what his own mind is dictating.
Hope this helps!