Lucio Barani was said to have gestured in the direction of Barbara Lezzi from the opposition Five Star Movement (M5S) on Friday.
Vincenzo D'Anna is thought to have repeated the gesture.
Female senators from various parties responded, demanding that Mr Barani apologise.
The Senate speaker suspended Friday's debate on Italy's constitutional reform bill in the subsequent pandemonium.
The two centre-right senators insisted their actions were misunderstood, but were nonetheless suspended by the speaker's council on Monday.
The speaker said the incidents were "so serious they offended persons and senators, and undermined the credibility of the institutions," news agency Ansa reported.
M5S Senator Alberto Airola was also suspended for a day for insulting members of government.

The incident happened as the 33-year-old walked under a railway bridge on Dumbarton Road, near the junction with Cable Depot Road, at about 22:00 on Saturday 10 September.
Both boys were described as being white, aged about 14 or 15 and wearing dark-coloured sportswear.
One of them had brown hair in a quiff.
The woman was taken to the Queen Elizabeth University Hospital for treatment and later reported the incident to police.
Det Sgt Kevin Mulvenna, of Police Scotland, said: "This was a completely unprovoked and senseless attack on this woman, which has left her blind in one eye. The youths responsible must be caught as soon as possible.
"To point a laser pen at someone is highly irresponsible. Extensive inquiries are ongoing to trace the two boys, with officers carrying out inquiries in the local area and studying CCTV footage to identify them."
He asked anyone with information to contact police.
Two Italian senators have been suspended for five days after allegedly making obscene gestures at female colleagues during a senate debate.
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