彼からそんな奇妙な行動を見るのは珍しいです

Meaning
it's unusual to see such a strange behavior from him

Vocab used in this sentence

he, his, him, boyfriend
から
from, at, because, out of, by, since, off, after
そんな
such, like that, that kind of
奇妙
strange, peculiar, weird, odd, queer, curious, oddness
a, the, na, nan, nai
行動
act, action, behavior, conduct, behave, behavioral, behaviour, demeanor, mobilization
o, the, to, wo
見る
see, watch, look, to see, to watch, show, view, to look at
to, of
a, the, is, am, are, will
珍しい
rare, unusual, usual, uncommon, curious, precious, rarity
です
is, be, are, am, that, away

Jeffrey van Binsbergen is a highly skilled developer, known for his expertise in optimalisations and AI.